Review links three B2 formation pathways to refractory-alloy performance

A critical review identifies three distinct formation pathways for B2 ordering in aluminium-containing refractory complex concentrated alloys, finding that the route associated with an ordered structure is closely connected to its stability, microstructure and contribution to mechanical performance. The authors warn that applying the broad label “B2 ordering” to ordered states with different origins and morphologies has led to inconsistent interpretations across the materials literature. The review examines B2 ordering through four connected themes: its thermodynamic origin, the mechanisms by which it forms, its thermal stability and its influence on mechanical behaviour.

Although each pathway produces an ordered B2 structure, the available evidence indicates that they differ in transformation mechanism and microstructural manifestation. The degree of ordering alone therefore provides an incomplete account of why aluminium-containing refractory complex concentrated alloys exhibit such varied reported responses. Reported mechanical behaviour associated with these alloys ranges from exceptional high-temperature strength to simultaneous improvements in strength and ductility.

The review links this diversity to the way B2 ordering develops and persists rather than treating every observed ordered state as equivalent. Its proposed framework explicitly connects formation pathway, degree of B2 ordering, microstructural evolution and mechanical properties, offering a common structure for comparing observations that may previously have been grouped under the same phase label.

Subject of Research: Review of B2 formation pathways and mechanical effects in aluminium-containing refractory complex concentrated alloys

Article Title: B2 ordering in Al-containing refractory complex concentrated alloys: composition–structure–property relationships

Article References: Yurchenko, N., & Stepanov, N. (2026). B2 ordering in Al-containing refractory complex concentrated alloys: composition–structure–property relationships. Journal of Materials Science. https://doi.org/10.1007/s10853-026-13650-7

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DOI: 10.1007/s10853-026-13650-7

Keywords: B2 ordering, refractory alloys, complex concentrated alloys, aluminium alloys, phase formation, microstructure, thermal stability, mechanical properties, materials review, ordering, Al-containing, refractory